Horn and/or tone box for talking machines, wireless loud speakers, and the like



Jan. 29, 1929.

W. BENNETT ONE BOX FOR TALKING MACHINES, WIRELESS LOUD SPEAKERS, AND THELIKE Filed May 22, 1925 R MAL/A ill Patented Jan. 29, 1929. p

UNITED' STATES PATENT OFFICE;

WILLIAM BENNETT, 0F TEMIPEfNEARc SYDNEY, NEW SOUTH WALES, AUSTI RALIA,[AS-.- SIGNOR OF TWO-THIRDS TO GEORGE ROCKLEY AND ALBERT CHALLEN, BOTHOF BEXLEY, NEAR SYDNEY, NEW SOUTH WALES, AUSTRALIA.

HORNAND/OR TONE BOX FOR TALKING MACHINES, WIRELESS LOUD SPEAKERS,

AND THE LIKE.

Application filed May 22, 1925, Serial No. 32,088, and in Australia Thisinvention has been specially devised to provide a horn and/0r tone boxor amplifier for talking machines, wireless loud speakers and other likesound distributers which will emit sounds and tones, say of the voice,music, and the like clearly and of considerably increased and richervolume and without the vibration and distortion generally present insuch apparatus heretofore and further which is comparatively cheap andof strong and of lasting construction.

This improved horn and/or tone box has an ordinary body or a shell ofsheet metal pressed, stamped out, or otherwise made of the requiredconfiguration which is preferably that of a downwardly curving trumpetand according to this invention the inside of the shell or body isworked to an extremely smooth surface and has curved joinings so that itpresents no angles or obstructions to sound passage therethrough, andthe outside of said body or shell is coated or covered with a more orless resilient substance or material adapted to be wrapped or laid orspread or cast or moulded on the metal and this to be of graduated ortapering thickness and which said dampen coating as it will hereinafterbe termed must be capable of dampening vibrations of sounds whose wavesstrike or impinge upon the inside smooth face of said body or shell andalso be capable of more or less efiectively preventing metallic ring insaid body or shell.

After much trouble/and experiment 1" have ascertained that thesubstances and materials best suited for the purposes of the desiredwrapping or coating on the outside of the metal horn are compositions ofplaster of Paris and pitch and compositions containing sand intermixedwith sawdust, cow hair and glue and with or without wire reinforcementand l have successfully used rubber, compressed paper, cardboard andfelt.

The substance or material may be cast, plastered, spread, wrapped orlaid upon the body or shell in one thickness or in more or less thinlayers fastened to the shell together by glue or other adhesive andpref' erably the depth or thickness of the so formed outerdampen-coating tapers from the smaller end of the body or shell where itis thickest owing to the sound vibrations being there the heaviest toits thinnest part at V elled or plated or lacquered June 26, 1924.

the inlet end or mouth whereat sound vibrations are much diminished Butin order that this invention may be readily carried into practicaleffect the same will now be described with reference to the drawingsaccompanying and forming part of this complete specification.

Fig. l is a plan, Fig. 2 is a front View and Fig. 3 is a longitudinalsectional elevation respectively of this improved horn and/or tone boxspecially constructed for a talking machine.

The body or shell 4t and/ or amplifier is of sheet metal say galvanizedor black sheet iron of suitable gauge ac cording to the length thereofalthough 24 to 26gauge has been found most satisfactory for ordinarypurposes and it is made with configuration similar to that of curvedtrumpet but of oblong cross section and made with soldered or pressed,curved and smoothed joints and with or without a wire reinforcement sayof light wire around the outside and preferably soldered to the shell,The inside face of said shell 4 is either or otherwise more or lessperfectly smoothed so as to present unobstructed area to sound wavesimpinging thereupon and the outside of said shell l has awrapping orcoating 5 possessing the unaltties hereinbefore set forth andhereinafter fully defined.

in a preferred application of the dampenof this improved horn varnished,enamcoating 5 after the outside of the shell l is painted varnished orenamelled (which is preferred) with several coats to prevent rusting andalso to make a base course a heavy coat of sawdust is spread thereonbefore the last coat of paint or varnish is dry, and upon thisfoundation the composition of plaster i of Paris, liquid glue and cowhair islaid The preferred composition consists of by WQIQl'llJZ- 24parts of plaster of Paris,

6 parts of cow hair,

1 part of glue,

2 parts of water,

its

In another application of the'dampen-coatthe shell site about one-eighthof an inch at the mouth end. But if desired this coating may be made upof repeated applications of one over the earlier of sheets of cureclrubber fastened to the founolation and to each other by the rubbersolution so as to build up the outer Wall to reciuirerl thickness Inanother application of the dampen-coatafter the first rust resistingcoating of the outside of the shell 4 has been applied instead of sheetsof rubber layers of cornpressecl paper preferably blotting paper or hfcardboard or of felt or of such like are earlier said sountl will'haveless glued to the shell 4 and piled one on the to one another to make upthe requisite thickness of saicl nlampen-coating 5 which then may beexternally finished by' paint or the a a fit is preferred that thisimprovefl dampenc aterl horn should be. connected to the sourceorintalr-e of the sound to be distributed by means of a tapered thimbleor tube 6 so that to the souncl there W'll be less obstacle thanheretofore to its spr'eacl or divergence ancl force of attack on theinside face of the horn. This thimble- 6 is say of Wrought or cast ironcopper or brass or some other metal but is preferably made ofmetal ofsonorous quality anal said dissolved in benzine v 5 I v sleeveispositional in the intake end of the inner tube 4: and retained thereinby soldering or is otherwise afiixerl.

The horn and/or tone structecl as before d escribedris fastened in placein a talking machine cabinet as ortlinarily by Wooden cleats or screwsor other fastening devices. J

In use the sound from the talking machine or amplifier diaphragm and thelike enter the tone horn l-li through the sleeve 6 which directs thesountl Waves forwardly in a more or less spreacling or diverging streamand as saicl Waves impinge upon the insicle face of shell 4 which beinginwardly smooth does not offer any resistance'thereto any vibrations andor clistortion of said souncl are clampenecl and more or less absorbedby the resilient Wrapping or coating 5 on the shell l and any metallicring in or of the shell l is more or less prevented and the soundissuingfroin the horn is considerably clarified and freed from m'brationand distortion and as well increased in volume,

What 1- claim as my invention and rlesire to secure by Letters Patent is2- 1. improved horn or the like for the purposes set forth, having aninner metal shell and an outer covering therefor tapering in thicknessfrom the inlet-end toward the outlet-end, seirl covering being of asoundabsorhing substance,

:2 A horn or the like for the purposes set forth, having an inner metalshell and substance consisting of a mixture of plaster of Paris, cowhair and glue.

In testimony whereof I have signed my name to this specification. i

box 4 5 I so con-' outer covering therefor of a sound-absorbing

